Vol. 47 No. 4/2000 1179–1182 QUARTERLY Communication

A polymorphism at codon 72 of gene p53 results in the presence of either arginine or proline at this position. We investigated the distribution of p53 codon 72 polymorphism in cervical cancer patients and a control group of healthy women from Poland. Our results do not confirm the hypothesis that the p53 codon polymorphism could play a role as a factor for squamous carcinoma of the cervix.

The p53 gene is polymorphic at the codon for amino acid 72 of the protein and encodes either proline (codon CCC) or an arginine residue (codon CGC) at this position.A potential association of p53 codon 72 polymorphism with an increased susceptibility to malignant conversion has been examined for different neoplastic diseases including lung cancer [1], hepatocellular carcinoma [2], ovarian and endometrial cancer [3,4].
The first investigation concerning the role of p53 codon 72 polymorphism in human papillomavirus-associated cervical cancer suggested that two polymorphic forms of the p53 protein differ in their susceptibility to degradation mediated by the E6 oncoprotein of human papillomavirus (HPV).Moreover, the frequency of the two alleles in cervical cancer patients compared with the control group revealed a striking overrepresentation of homo-zygous arginine-72 p53 [5].Epidemiological studies undertaken in larger populations and in different geographical regions did not confirm such correlation between the polymorphism at codon 72 of p53 and the risk of cervical cancer [6][7][8][9][10][11][12].
The purpose of our study was to examine whether p53Arg at position 72 could represent a risk factor for HPV-associated cervical carcinoma in the Polish population and to compare distribution of p53 codon polymorphism in the Polish population to other ethnic groups.There are no other data concerning this subject in Poland so far.

Patients.
A group of 44 squamous cervical cancer patients treated in the Oncology and Radiotherapy Clinic of the Medical University of Gdañsk, of which 22 (50%) were HPV-positive, was investigated.The patient population was in different clinical stages of squamous cell carcinoma of the cervix.The control group consisted of 52 healthy women undergoing routine gynaecological examination.
Detection of HPV DNA.HPV positivity was determined by the Hybrid Capture System according to the manufacturer's specifications.Samples were examined in the Department of Virology, National Institute of Hygiene in Warsaw (Poland).
Polymorphism analysis.Analysis of the p53 genotype at position 72 was performed by the PCR method with specific primers for the arg and pro alleles, described by Storey et al. [5].Modifications in detection and visualisa-tion of the PCR products were introduced: PCR products were separated on 8% polyacrylamide gel and stained with silver.
Statistical analysis.Data analysis was performed using the Statistica version 5.1 software.Chi-squared test with Yates correction was used to assess differences in the proportions of the p53 codon 72 genotypes between the two groups of cervical cancer patients (HPV-positive and HPV-negative) and also between all cervical cancer patients and the control group of healthy women.

RESULTS
Genomic DNA from both groups of women was analysed to determine the distribution of p53 codon 72 polymorphism.We examined a total of 96 individuals: 44 cervical cancer patients and 52 healthy women.The prevalence of the arg/arg alleles did not significantly vary between HPV positive (n = 22) and HPV-negative (n = 22) cases of cervical cancer (P = 0.9).Moreover, there was no difference in genotypes distribution between the non cancer control group and cervical cancer patients (P = 0.98).The results are summarised in Table 1.

DISCUSSION
Similar to previous studies [6][7][8][9][10][11][12] our results related to the genetic susceptibility to cervical cancer in HPV-positive women, do not support the proposed association of the arg genotype in codon 72 of p53 with an in- creased risk of cervical cancer [5].We found that differences in the frequency of the arg genotype in HPV-positive and HPV-negative cervical cancer patients and also in the non cancer control group as compared with all cancer patients are not statistically significant.A comparison of different populations is presented in Table 2.The high frequency of the arg genotype (73.1%) in Polish women is similar to the Spanish population (79%) [13] rather than to the geographically closer German population (55.7%) [11].The low percentage (3.8%) of the pro genotype makes our population most similar to the English population (4%) [10] and to the Mexican-American group (2.5%) [14].
In conclusion, our data show a different pattern of arg/pro allele distribution as compared with other populations and our results do not confirm the hypothesis that the p53 codon polymorphism could play a role as a factor for squamous carcinoma of the cervix.
We wish to thank Dr. Marek Tomasz Szkoda from the National Institute of Hygiene in Warsaw (Poland) for introducing us to the Hybrid Capture method.